emjay
+1y
Wrong. Those 3 tubes are called PAIR tubes, or Pulse Air Injection Recirculation. What these do is at certain demand loads they pull fresh air in from the air cleaner and feed oxygen to the catalytic converters. Reed valves on the air cleaner prevent exhaust gasses from blasting in to the air cleaner for all other times, they only open to suction FROM the exhaust. This is necessary for the older catalytic converters to operate properly. Newer cats use an alloy called Cerium which makes this unnecessary. That's why older cars/trucks have PAIRS (or smog pumps or air pumps) and newer ones don't.
IF you have an old OEM cat that's still good and you are required to have emissions then YOU NEED THESE TUBES otherwise they will overheat, not react properly, not get their oxygen, and CLOG. Clogged cats KILL engines. They also KILL reed valves and allow exhaust to be forced into the air cleaner and thus into your engine. Ask me how I know this
IF you have NEW cats that do have Cerium in them then you can plug these right up.
IF you are in a non-emissions area and have gutted your cats then these are worthless. You will still need to maintain something in your exhaust